1. Field of Invention
This invention pertains to a modular wall system adapted for use as part of a clean room structure. More particularly, the present invention relates to a modular construction wherein wall panels can be quickly assembled or disassembled, yet wherein the assembled wall structure is capable of being sealed at the juncture of each attached wall panel to develop a Class 10 clean room status.
2. Prior Art
Clean room structures are especially constructed enclosures which provide an environment free of dust and typical contaminating particles which are normally present in air. Such environments are required for the manufacture of sensitive electronic components, particularly integrated computer chips having hundreds of tiny circuits whose effective operation depends upon the absence of foreign materials. Such structures are classified, based upon the number of particles present in a cubic foot of air space. For example, a Class 10 clean room means that there are only ten or less particles of 0.5 microns in size or larger in a cubic foot of air space.
The construction of such specialized structures has traditionally required permanent construction techniques which offered little flexibility in terms of structural modifications in disassembly. Such permanent construction was believed necessary in order to develop the airtight enclosure required to meet clean room standards.
U.S. Pat. No. 4,667,579 discloses a modular construction which meets the stringent, airtight standards for a clean room but provides flexibility in disassembly and modification to variable structural configurations. A principle characteristic of the disclosed clean room includes the components and techniques for attaching a vertical strut or stud at the juncture of two panel elements in a manner such that complete sealing against particle infiltration was accomplished. These techniques included the use of a conventional steel stud which was slotted to receive a clip, wherein the mated clip was attachable to lateral flanges of two abutting panel sections. Such a configuration is shown in FIGS. 4 and 5 of the referenced patent.
Although such structure represented a significant improvement over prior art methods and apparatus for construction of modular clean room assemblies, tolerances of each component allowed a degree of misalignement which necessitated careful attention during assembly. Although careful construction techniques have traditionally been required in fabricating clean room structures, it would be a substantial improvement in the art if clean room structural components were self-adjusting to establish coalignment of panel sections within the single plane and complete sealing of panel junctures.
The concept of utilizing lateral flanges on separate panel sections is not unique to clean room construction. For example, U.S. Pat. No. 4,649,684 by Petree shows a panel section which includes lateral flanges capable of being clipped together by a channeled chip which enclosed a resulting "T" configuration formed by the abutting lateral flanges. Other techniques for structurally interlocking panel sections are represented in U.S. Pat. No. 4,461,131 by Pressell, U.S. Pat. No. 2,867,857 by McCarthy and U.S. Pat. No. 3,975,880 by Fischer, Jr. None of these patents, however, provides structure suitable for clean room construction wherein they are adapted to seal at the panel juncture and develop the level of parallel alignment which is needed to ensure full structural integrity in accordance with clean room specifications.